WEST SAN GABRIEL VALLEY — As a critical chapter closed in the 30-year saga of the Long Beach Freeway fight, supporters were celebrating and opponents were regrouping this week in the wake of the federal government's formal approval of an environmental study on the project.

Freeway advocates were jubilant over the news that on Monday federal officials had signed the final environmental impact statement required to complete the 6.2-mile gap. The decision provides the basis for ending a federal court injunction blocking the freeway's extension from the San Bernardino Freeway (10) in Alhambra and the Foothill Freeway (210) in Pasadena.

The freeway's completion, he said, will be "good for business, good for the environment and good for people."

Peter Lyman, president of the Pasadena Chamber of Commerce, said, "It's been a long time coming."

However, the opposition, centered in South Pasadena, resolved to fight even harder against the proposed route, known as the Meridian Variation because it roughly parallels Meridian Avenue through South Pasadena.

"The new card dealt means this will end up in court," said South Pasadena Councilwoman Evelyn Fierro.

The environmental study itself, more than four years in the making and several inches thick, was required as a result of a 1973 court injunction against the California Department of Transportation.

Its key conclusions are not news to opponents or supporters.

In justifying the project, the environmental study said the eight-lane freeway, including two lanes for high-occupancy vehicles such as buses and vans, would provide "substantial relief to congested city streets and freeways as far away as the cities of Glendale and Whittier."

Without completion of the freeway, the daily traffic on the Glendale Freeway (2), the Harbor Freeway (110) and the Pasadena Freeway (110) "will further exceed capacity and traffic congestion will be worse than the already unacceptable levels," it said.

In weighing the options of building the freeway versus not building it, the report projected a $5.3-billion savings over a 20-year period if the freeway were built. This amount, based on 1986 dollars, was calculated by considering, among other things, the value of the time and distance to commuters.

Mass transit alone cannot meet the transportation needs for the area the freeway would serve, the report said. However, it said that the high-occupancy vehicle lanes planned for the Long Beach Freeway extension would serve a crucial link between the San Bernardino Freeway and the Foothill and Ventura (134) freeways.

The report also explains why transportation officials rejected the "low-build" approach often advocated by South Pasadena officials, an approach primarily limited to expanding the capacity of existing streets.

The environmental study said that although the creation of a "super street" would reduce traffic congestion in a few areas, it would make traffic worse elsewhere. This, the report said, also would create more air pollution and noise problems.

Before the federal officials signed the environmental document Monday, South Pasadena Mayor Dick Richards and Councilwoman Fierro had planned to travel to Washington, D.C., to meet with top federal highway officials. Richards said he and Fierro are still going.

A face-to-face meeting, they said, will help them determine details about the project and, in the long run, help in the opposition's attempt to forestall federal officials from granting final approval of funding and construction.

On Monday, the mayor, along with other local officials and representatives from environmental groups, will brief the community on the continuing fight against the freeway proposal. The meeting will start at 7 p.m. at the South Pasadena Junior High School Auditorium, 1524 Fair Oaks Ave.

"The community is pretty solidly behind fighting this," Fierro said.

Despite the opposition, Caltrans Regional Director Jerry Baxter said he hopes that South Pasadena representatives will participate in an advisory panel, a key requirement set out in the environmental impact statement.

This advisory panel, Baxter said, will work with state and federal officials on devising ways to reduce the impact on the environment.

During the next two to three weeks, Baxter said, Caltrans will put together the panel, made up of about a dozen members. It will represent a diverse group of civic, community and governmental officials and leaders from preservation and environmental groups--including opponents and supporters.

"I'm not sure if South Pasadena will come to the table," Baxter said. "But we're really serious about seeing how creative we can be. We're going to go into it with an open mind.